New research shows that when it comes to emotions, the male and female brain really are wired differently

At breakfast the other day, I made the mistake of opening my laptop when my wife felt like talking. I was happily trolling YouTube, but Ruth wanted to dish about how her friend's nanny is becoming a total hoochie mama.

"You're fun this morning," Ruth sniffed when she realized I wasn't listening. (I was watching clips of lunatics who like to parachute off of skyscrapers.)

On the surface, we were at a typical male-female impasse. Ruth wanted to connect; I just needed a little space. Moments like this happen all the time with us--like the previous night, when I became a jaw-­gritting mute after Ruth casually mentioned that an ex-boyfriend from college had made her a Facebook friend. She was like, "Omigod! His kids are so adorable!" I was like, "Rrrrrrr."

Clearly this pattern was telling us something, and not just that we should spend less time online. It turns out that her craving for chitchat and my habit of shutting down are pre-existing conditions--gender differences that go back hundreds of thousands of years.

A Great Divide
The female brain, and therefore Ruth, has a meatier frontal cortex than this grunting, monosyllabic husband of hers. That part of the brain is associated with complex functions--like language and decision making. Ruth also packs more power in parts of her limbic cortex, which stokes her feelings and her need to "share." Finally, because guys tend to process nonverbal expressions less efficiently than women do, I was too slow to read Ruth's facial cues telling me, "Laptop down and listen up, buddy boy."

In short, it was our biology talking (or avoiding talking), at least if some fresh scientific findings are true. Until recently, neuroscientists believed that brain differences between the sexes were confined mainly to reproductive behavior. But a surge of research using functional magnetic resonance imaging (fMRI) and other noninvasive scans of male and female brains suggests that sex plays a role in memory, hearing, vision, emotion, even how we chill out. By extension, we could be on the verge of solving such imponderables as why men leave the toilet seat up and women dig Josh Groban.

"The brains of men and women, while similar in many ways, are more different than most scientists ever realized," says Larry Cahill, Ph.D., an associate at the University of California, where he researches emotion, memory, and the brain.

Consider the brain idiosyncrasies Cahill discovered by doing scans on men and women at rest. His team noticed stark differences in the behavior of the amygdala, the almond-shaped structure that helps regulate human emotion. "Men's amygdalas interacted more with brain regions involved with the external world, like vision and hearing," Cahill explains, "while women's amygdalas interacted more with their internal world--the organs, including those involved with reproduction and feelings." In English, that means guys fixate on their surroundings--a primordial defense against predators, including those of the Facebook variety (this might also explain a raised toilet seat as a territory marker).

Last year researchers at the University of Pennsylvania used scans to try to understand how men and women handle stress. Among the findings? Anxiety activates the "tend and befriend" reaction in women's limbic systems and the "fight or flight" response in men's prefrontal cortexes. Translation: Under pressure, women reach out, while guys go Rambo. In 2004, researchers at Emory University discovered differences in how men's and women's brains respond to sexual stimuli--the takeaway being that sexual images fire male emotions (visible as activity in the amygdala) faster than a clip of Michael Jordan's farewell game. Women's brains go, Eh.

A Gray Matter
Of course, neat conclusions like this can lead to trouble. A couple of years ago, Louann Brizendine, M.D., a researcher with modest credentials (Harvard med school, Yale med school, blah blah blah), made a splash and then drew criticism for suggesting that the female brain was practically a species all its own. Her point was that female hormones like estrogen, progesterone, and oxytocin, as well as unique qualities in the size and function of parts of a woman's brain, radically distinguish the female mind. The result, she argued, citing colorful scans, is that women tend to be more communicative, more cooperative, less aggro, and generally more empathetic than men. "These differences in function and structure tell the story of how different men and women are," Brizendine says.

Begin to tell the story, is more like it. Some researchers say that structural differences in the brain don't mean squat when it comes to behavior. Others argue that there are far more overlaps among male and female brains than there are differences and that other factors--environment and upbringing, for instance--are every bit as important as your hormones and the size of your hippocampus in influencing how you behave.

It's easy to draw provocative conclusions, says psychologist Susan Pinker, author of The Sexual Paradox. "But people are individuals, so they don't divide cleanly into camps on most psychological measures," she says. Even so, average differences in how men's and women's brains look and function do suggest a biological basis for, say, why he's not getting your hint that cargo shorts are not appropriate attire for dinner with your parents.

At the very least, all this brain gazing helps me understand why my wife talks and I tune out. That's not to say I'll be adding Josh Groban to my play-list, but at least I'll try harder to listen when Ruth wants to sing his praises. Meanwhile, I shared some of this research with her, and she likes knowing that something older than us is at work inside our heads when I appear not to have evolved beyond the Neanderthal.

"We're only just beginning to understand how men and women operate neurologically," Cahill says. "We know differences do exist, but we don't know yet what those differences mean. Check back with me in 30 years and I'll tell you where we're at." I wonder if Josh Groban will still be singing the same goopy songs then.

Mind games
Better communication in three easy steps

Tell him to quit solving already
"Some studies show that men's brains respond to stress by activating a part of the limbic system that prompts action," psychologist Susan Pinker says. What does that mean to you? "If you want a man to listen sympathetically instead of solving the problem for you, you'll have to say so," she says.

Give him a chance to respond
"Men don't pick up emotional nuance as quickly as women do, and women put emotion into words faster," says researcher Louann Brizendine, M.D., author of The Female Brain. In women's brains, the left and right hemispheres more often work simultaneously. This means women relay messages from the amygdala, where emotions are triggered, to the brain's left hemisphere, where those emotions are verbalized, more quickly.

It can be a difference of just milliseconds, but that often means the difference between having a normal conversation and thinking accusatory thoughts like "You're not really listening to me."

So be patient, and give him a chance to formulate a response to whatever you're saying.

Talk about it tomorrow
Sandra Witelson, Ph.D., and her team of researchers at McMaster University in Hamilton, Ontario, found that women have more neurons in parts of the cortex of the temporal lobe, which is associated with processing and understanding language, than men do. "That plays a role in why women, on average, perform better than men on verbal tasks," UC Irvine neuroscientist Larry Cahill, Ph.D., explains. Bottom line: Sometimes not talking about his emotions is the only way he can deal with them. Letting a day go by before coming back to the issue might get him to open up.